source: orxonox.OLD/branches/terrain/src/lib/util/filesys/binary_file.h @ 9414

#ifndef _BINARY_FILE_H
#define _BINARY_FILE_H

#include <stdio.h>
#include <string>
#include "byte_order.h"
#include "file.h"

enum TerminalType       { TT_INT = 4, TT_BYTE = 1, TT_SHORT = 2 };

/**
 * Holds the compiled semantic-string.
 */
struct DataSemantics {

        DataSemantics()
        {
                totalSize = 0; chunks = NULL;
                quantifier = 1;
                isTerminal = false;
                numChunkNodes = 0;
        }

        ~DataSemantics() 
        {
                delete[] chunks;
        }
        
        int                     totalSize;
        int                     quantifier;
        int                     numChunkNodes;
        bool                    isTerminal;
        union {
                int                             type;
                DataSemantics   **chunks; 
        };      
};

typedef DataSemantics *pDataSemantics;

class BinaryFile : public File {
        public:         
                BinaryFile()
                        :       File( "" ),
                                byteorder( NATIVE_BYTEORDER )
                { /* nothing to be done */ }
                
                BinaryFile( const std::string& _file )
                        :       File( _file ), 
                                byteorder( NATIVE_BYTEORDER )
                { /* nothing to be done */ }

                BinaryFile( const BinaryFile& _file )
                        :       File( _file.name() ), 
                                byteorder( _file.getByteorder() )
                { /* nothing to be done */ }
                
                /**
                 * Reads a chunk of data based on the _semantics string. The string contains
                 * a description of how the bytes are laid out in the file. If you want
                 * to read out a struct which looks like this
                 * struct {
                 *              int     magic;
                 *              short   size;
                 *              float   x, y, z;
                 * };
                 * then the semantics string is "isf3". If you want to read 5 of these
                 * chunks, just put the whole string into paranthesis. "(isf3)5". Nifty, isn't
                 * it?
                 */
                void read( const char *_semantics, void* _buf, size_t& _bytesRead );
                
                /**
                 * The same as the read above, but with the ability to read multiple
                 * chunks once. Very useful if you don't know how many chunks you're 
                 * going to read at compile time.
                 */
                void read( const char *_semantics, int _chunks, 
                        void* _buf, size_t& _bytesRead );
                /**
                 * Writes a chunk of data based on the _semantics string. The string contains
                 * a description of how the bytes should be laid out in the file. Have a look
                 * at the description to read().
                 */
                void write( const char *_semantics, void* _buf, size_t& _bytesWritten );
                inline void seekg( int _pos )
                {
                        fseek( handle(), _pos, SEEK_SET );
                }
                /**
                 * @brief Sets the byteorder of the file. The order affects all subsequent
                 * calls to write() and read(). It it is not wise to change the order
                 * in the middle of reading a file. You're totally on your own.
                 */
                inline void setByteorder( ByteOrder _order ) 
                { byteorder = _order; }
                
                /**
                 * Returns the file's byte-order.
                 */
                inline ByteOrder getByteorder() const
                { return byteorder; }
                
        private:
                pDataSemantics compileSemantics( const char *_semantics );      
                ByteOrder               byteorder;
};

#endif